1. Field of the Invention
The present invention relates to a door lock with two knob (handle) assemblies, and more particularly to a latch driving unit for the door lock which is provided in an exterior knob assembly to connect the latch assembly to an interior knob assembly.
2. Description of Related Art
A conventional door lock with two knobs or handles etc has an exterior knob assembly provided at an exterior side of a door, an interior knob assembly provided at an interior side of the door, and a latch assembly received in the door and connected between the exterior knob assembly and the interior knob assembly.
With reference to FIGS. 7–8, the exterior knob assembly (30) has an exterior knob (31), a locking core (32) received in the exterior knob (31), a turnable barrel (33) connected to a rear end of the locking core (32), and a latch driving unit (34) connected to the latch assembly (not shown) and the interior knob assembly (not shown).
The latch driving unit (34) has a tubular cam (35) received in the turnable barrel (33). A resilient member (36) is received in the tubular cam (35). A tongue of the locking core (32) is inserted in a first end of the tubular cam (35), and a locking disk (37) is provided at a second end of the tubular cam (35) and has wings (not shown) radially extending outwards from the turnable barrel (33). A cap (38) is securely provided at a rear end of the turnable barrel (33), and a strip (39) is secured in the cap (38) and extends backwards.
When the exterior knob (31) is turned, the turnable barrel (33) and the tubular cam (35) are rotated, so a latch of the lock is pushed by the latch driving unit (34) to transversally move for opening the door.
In the conventional latch driving unit (34), the strip (39) has a plurality of nicks (not numbered) defined thereon. A user can bend the strip (39) at a proper nick corresponding to a thickness of the door and remove the unwanted part of the strip (39). However, the strip (39) is often broken at an incorrect nick and becomes too short for the door. Because the strip (39) is integrally formed with the cap (38) and the turnable barrel (13), it is impossible to individually replace the strip (39). Therefore, the exterior knob assembly (30) has to be abandoned, causing unnecessary cost and an inconvenience to assemble the lock.
Therefore, the invention provides a latch driving unit for a door lock to mitigate or obviate the aforementioned problems.